They've got movie-star charisma, with power (and talons) to match. But to raise chicks, snowy owls rely on the boom-or-bust market of their favorite prey: the humble lemming.

Scientists know just a few places where snowy owls breed regularly: Barrow, Alaska, is the only one in the United States. Perched between the Chukchi Sea—thick with ice even in July—and the hummock-and-pond vastness of the tundra, Barrow has a population of roughly 4,600 people and serves as the municipal center for the state's huge oil-rich North Slope Borough. A decade ago biologist Denver Holt, founder of Montana's Owl Research Institute, came here, drawn by the "mythic lure" of big white birds. Though many individual snowy owls winter on the Great Plains of the U.S. and throughout Canada, to observe Nyctea scandiaca in significant numbers, Holt says, "You have to come to Barrow."

Much of his summer fieldwork has focused on links between owl reproduction and lemming numbers. But as Barrow homes and businesses have expanded into snowy owl habitat—like the natural gas pumping station within sight of a nestful of chicks—Holt has become increasingly concerned with owl-human relations. "There's a long history of the native Inupiat people and owls living together here," he says. "The question is, will those traditions continue to be respected? Will Barrow make choices that work for people and owls?"

Where do snowy owls go when they leave summer breeding grounds? Tested on Barrow owls, a new satellite tracking system—using transmitters that weigh about an ounce and record data for more than a year—reveals that individual birds range through as much as a third of the Arctic. But before Holt's Owl Research Institute team could start collecting data, owls had to be caught. Dodging a snapping beak and sharp talons, Holt and colleague Laura Phillips gently untangled a female from a lemming-baited trap, then fitted her with a transmitter backpack. After release tagged birds preened, then flew undisturbed by the device's antenna, and rejoined their chicks. "We've worked on adults and young from 142 nests," Holt says. "Handling causes some stress, but we're extremely careful. Our research has never caused an owl to abandon a nest."

Most owl species depend on camouflage and stealth to survive, but "snowy owls seem to defy all the conventional owl wisdom," says researcher Mat Seidensticker. "They don't hide. During the breeding season they're flashing white beacons" against the treeless greens and browns of the tundra, hunting in Arctic summer's 24-hour daylight. Adult females weigh as much as five pounds and hurtle through the air on wings more than five feet across. Males are smaller and sleeker, with a top weight of about four pounds, but they're equally powerful fliers. Lemmings aren't their only prey: Snowy owls kill weasels and foxes, and even feed on other birds, including jaegers, eiders, and gulls. Diving out of the sky with long legs and talons outstretched, a snowy owl can drive away humans, dogs, even caribou that wander too close to its young.

Birds that remain in the polar north through winter manage to find food despite three months of total darkness. These stoic owls rarely seek shelter, even from roaring winds. Their plumage protects them so effectively that adults can endure temperatures as low as 40 degrees below zero. "Snowy owls," Seidensticker says, "are as well insulated as arctic foxes."

The pure white feathers of a male delivering a lemming to his mate do more than keep him warm. They also show that he's fully mature. Males don't lose the gray-brown banding that marks females and juveniles until they're three to four years old, and rarely breed before that. In years of peak lemming abundance, Holt and his team have observed older, highly aggressive males establishing nests with two different females. They hunt for both, and protect two territories that may each extend a half mile from their central nest mounds.

Bloody from tearing a freshly caught lemming into tiny mouthfuls, the female fed each of her offspring in turn. Females typically lay eggs two days apart; chicks hatch at roughly the same interval. In a clutch of six or seven eggs, the first chick hatched may be two weeks old before its youngest sibling emerges. "We've seen no signs of competition or favoritism in the nest," Holt says. "Snowy owls nurture all their chicks, even the smallest."

Harry Potter novelist J. K. Rowling cast a snowy owl as her orphaned hero's courier and companion. That seems perfectly fitting: Swift, strong, beautiful, and dauntless in caring for their young, these winged icons of the Arctic are magically fascinating—to boy wizards and scientists alike.

Can you identify the birds in your backyard? This newsletter tells youall about neighborhood birds and how to attract them. To subscribe, visitwww.ngbooks.org/birds, orcall 888-532-6789.

In More to Explore the National Geographic magazine team shares some of its best sources and other information. Special thanks to the Research Division.

Owls are among the birds of prey, or raptors, that are protected by federal and state laws—as well as international treaties—prohibiting their ownership in the United States without a wildlife or falconry permit. So kids inspired by Harry Potter's loyal snowy owl companion, Hedwig, won't be able to own one and train it to be their personal courier. If you are fascinated by these and other wild birds, you may learn more about them through programs run by places such as the Audubon Center for Birds of Prey (adoptabird.org) in Maitland, Florida, and the University of Minnesota's Raptor Center (raptor.cvm.umn.edu). By offering donations, individuals, families, scout troops, or school classrooms may help support the rehabilitation of the hundreds of injured or orphaned hawks, owls, falcons, kites, and eagles treated at the centers yearly. According to Audubon Adopt-a-Bird Program coordinator Paula Stack, people in every state and six foreign countries have "adopted" raptors by making donations to support the care of non-releasable birds perching permanently at the center's aviary. Classrooms use Stack's "Bird Buddy" kits to learn about their adoptees. Raptor Center programs help to raise local and national awareness about how birds' and humans' lives are affected by changes in our shared environment.

—Nancie Majkowski

Owl Research Institute www.owlinstitute.org/research.htmlView photographs of Owl Research Institute field biologists at work on their Barrow project. ORI is part of the nonprofit Ninepipes Center for Wildlife Research and Education near Missoula, Montana.

Natural Exposureswww.naturalexposures.comSnowy owls and other Alaska wildlife are a special interest for photographer Daniel J.Cox. Examples of his natural history photography on this site include many shots of this wild bird's preferred food, lemmings.

Audubon's Christmas Bird Countwww.audubon.org/bird/cbc/owl_home.htmlLearn about an opportunity to spot a snowy owl during the annual Audubon Christmas Bird Count. During this event in 2000, observers all over the U.S. and Canada reported seeing 212 snowy owls, including one in Oklahoma.

Fuller, Mark R., and others. "Raptors." In Our Living Resources: A Report to the Nation on the Distribution, Abundance, and Health of U.S. Plants, Animals, and Ecosystems. U.S. Department of the Interior. National Biological Service. Available online at biology.usgs.gov/s+t/noframe/b024.htm.